Ok, I'll bite. I've been coding for almost 25 years so have seen various things come and go, so hopefully have a bit of capital in the bank.
Don't get me wrong, a HTML5 radio button is a beautiful thing, and sometimes React is a hammer and everything is a nail.
However, I think something that OP doesn't mention super explicitly in their post is the codebase they are working on is probably a React codebase. React is a great abstraction for building UIs. I've built a ton of them and the complexity only needs to go above a certain degree until you need a way more descriptive way of explaining your UI based upon other state, instead of trying to wire a load of DOM elements together.
If you are already using the React ecosystem, for things like form validation (again, possible with HTML5 but as soon as the complexity cranks or you can't use the server - you probably need a library), then using something like Radix is a great choice, OP even mentions how although it's not technically a visible radio button that is shipped to the DOM, it acts like one for a11y reasons, and this is due in part because it's very, very easy to write inaccessible HTML. And ShadCN is pre-made components on top of that, and they all work pretty well together.
Nothing is perfect, but even in my "old man yells at cloud" era, I personally don't think this one is worth yelling at the cloud for.
React has it's problems, but for me one of the most appealing things is doing away with this magic attribute sprinkling that is a maintenance nightmare and just going all in on JSX.
The author seems to wear their support of capitalism "on their sleeve", so acting in their self-interest is endemic. At the risk of sounding bitter, I imagine these problems aren't trendy enough to solve yet, or maybe they just had something akin to blinkers on en route to their hike.
I think there would be some appetite but I cannot imagine the short term chaos it would cause. Surely it would cost the country a fortune and also I could see insurance companies driving up the cost of premiums.
I understand the need to make a living but hard to take this stuff seriously/sincerely with the, "and buy my course!" angle.